Supplementary file 1_Trade-offs in adaptation to water-related risks: modeling how climate services can influence pathways to transformation.pdf

Climate services play a central role in adaptation strategies to water-related risks, yet the long-term implications of relying on different types of climate information remain poorly understood. This paper presents a system dynamics model that explores how short-term and long-term climate services influence adaptation trajectories balancing agricultural production and wealth generation with water management and ecosystem protection. We apply the model to a synthetic case study where water scarcity poses the main risk for agriculture, considering precipitation forecasts as the main climate service. Short-term climate services (e.g., sub-seasonal forecasts) prioritize immediate risks and can facilitate reactive adaptation, such as rapid reservoir expansion and agricultural intensification. Long-term climate services (e.g., climate projections), by contrast, can support strategic planning and promote transformative measures, such as ecological restoration. Our model shows trade-offs between rapid wealth generation and long-term sustainability. Scenarios dominated by short-term climate services lead to faster economic growth, but also frequent and prolonged water crises. In contrast, reliance on long-term climate services can help build resilience and prevent crisis, but lead to lower economic returns. Mixed scenarios can avoid the worst outcomes, though they remain unstable and highly sensitive to climatic variability and shocks. Under climate change, increased variability in water recharge amplifies the demand for reactive measures, reinforcing short-term feedbacks and amplifying the risk of maladaptation. These findings highlight the importance of providing adaptation planners with long-term climate services that support the development of sustainable options while reducing the pressure of immediate threats. The model offers a conceptual framework for anticipating maladaptive patterns and emphasizes the need to balance short- and long-term objectives in coping with climate change.